Portable entertainment and communication equipment have been proliferating, including devices such as cellular phones, portable DVD players, MP3 players, and portable computing devices.
In all of these examples, audio communication is a large part of the user experience. In order to increase convenience and audio quality and to provide privacy, one-way headphones or two-way headsets are employed.
For added convenience, wireless headphones/headsets are available. For example, Bluetooth headsets are available for telephone conversations as well as headphones for audio listening. Because the headphones/headsets are wireless, they are required to provide their own power source, typically a battery (wired headphones/headsets are powered by the base system). Many use rechargeable batteries and require a method for recharging the batteries.
Prior art battery charging methods are described below:
In FIG. 1, representing prior art, the power source 1 provides input via a conductive means 6 to a power adapter 5. The power adapter 5 provides power to the wireless headphone/headset 4 via a conductive means, typically a power cable 3. The cable is connected to the wireless headphone/headset via a mating connector pair 7, 8. The power source 1 can be an AC line source. The power adapter 5 would convert the AC line source to DC.
In FIG. 2, representing prior art, the power source 10 can be a regulated DC source, removing the need for a separate power adapter. In this case, DC power is delivered to the wireless headset/headphones 11 via a conductive means, typically a power cable 12. The cable is connected to the wireless headphone/headset via a mating connector pair 13, 14. The power source 10 can be the regulated DC output of a powered Universal Serial Bus (USB) socket.
FIG. 3, representing prior art, describes the battery charging mechanism of a wireless headset/headphone 25. Power is provided to the wireless headset/headphone 25 via a conductive means, typically a power cable 30. The cable is connected to the wireless headphone/headset 25 via a mating connector pair 31, 32. Power is input to a battery charging circuit 26 which manages the charging of the battery 27. Power is then provided to the rest of the system 28, which interfaces the transducer(s) 29 in the case of a headphone, or transducer(s) 29 and microphone 24 in the case of a headset.
FIG. 4, representing prior art, describes a wireless battery charging mechanism. The power source 40 provides input via a conductive means 41 to a power adapter 42. The power adapter 42 provides power to the electronic device 44 via wireless means, typically inductive coupling 43.
As improvements of technology become available, there is an opportunity for further reduction of size and weight of wireless headphones/headsets. Wired methods of recharging batteries in wireless headphones/headsets add size by way of the necessity of connectors and increase the risk of failure via failure of mechanical components caused by fatigue and corrosion of contact elements. Furthermore, the end user complexity is increased by a wired-based recharging procedure.